Influence of the Welded Joint on the Mechanical Behavior of Steel Piles during Static and Dynamic Deformation

Abstract:

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During manufacturing the welded joint of steel structures, residual stress is produced and weld
metal is used inevitably. And residual stress and weld metal influence on the static and dynamic mechanical
behavior of steel structures. Therefore, to predict the mechanical behavior of steel pile with a welded joint
during static and dynamic deformation, the research on the influence of the welded joints on the static and
dynamic behavior of steel pile is clarified.
In this paper, the residual stress distribution in a welded joint of steel piles was investigated by using
three-dimensional welding analysis. The static and dynamic mechanical behavior of steel piles with a welded
joint is investigated by three-dimensional elastic-plastic finite element analysis using a proposed dynamic
hysteresis model. Numerical analyses of the steel pile with a welded joint were compared to that without a
welded joint with respect to load carrying capacity and residual stress distribution. The influence of the
welded joint on the mechanical behavior of steel piles during static and dynamic deformation was clarified by
comparing analytical results

Abstract: Detailed two- and three-dimensional finite element analyses are performed to develop an engineering method to estimate elastic-plastic J for cracked structures under combined primary and secondary stresses, based on the V-factor. Extensive analyses with a wide range of geometry and load combination are considered. The results suggest important factors affecting the value of the V-factor. The most important one is the load magnitude, parameterized by the proximity of plastic yielding. The second one is the relative magnitude of the secondary stress to the primary stress. Although the effect of material, in particular materials with Lüders strain seems to be present, such an effect could be neglected, compared to those of the above two parameters. Based on the present results, an engineering method to estimate J for combined primary and secondary stress can be proposed using
bilinear equations in terms of the above two parameters.

Abstract: During the welding process to make welded joints, residual stress is inevitably generated
and weld metal is used. Welding Residual stress is influenced on the behavior of welded joints under
monotonic and cyclic loading. And the weld metals used in welding process have different
mechanical characteristics than structural steels. Therefore, to accurately predict the hysteretic
behavior of welded joints, the effect of residual stress and weld metal must be investigated.
In this paper, the residual stress distribution in a welded tubular T-joint was investigated by
carrying out three-dimensional non-steady heat conduction analysis and three-dimensional thermal
elastic-plastic analysis. To consider a effect of base metal(SM490) and weld metal(E71T-1), a cyclic
plasticity model was formulated based on monotonic and cyclic loading tests. And the formulated
model was applied to three-dimensional elastic-plastic finite element analysis. The effect of residual
stress and weld metal on hysteretic behavior of a welded tubular T-joint was investigated by carrying
out numerical analyses considering residual stress and cyclic plasticity model of base metal and weld
metal respectively.

Abstract: The article proposes boring shaft lining used super strength steel fiber concrete and double steel cylinder to solve the problem of the construction of shaft lining in deep alluvium of 700~800m, and studies the mechanical characteristics and failure of the shaft lining structure based on the model testing. The studies indicates that boring shaft lining structure used super strength steel fiber concrete and double steel cylinder may greatly improve the capacity of the shaft lining, the ductility of common high strength concrete shaft lining, obtains good plastic characteristics and upgrades the reliability of the shaft lining structure. In addition, strengthening coefficient of super strength steel fiber concrete based on theoretical analysis and experimental results, providing the design references for the engineering application of the new type shaft lining structure.

Abstract: The numerical simulation calculation on round steel-tubes reinforced with CFRP sheets was done through the large-scale finite element software ANSYS. In this research, four factors were comparatively analyzed so as to obtain the influence of them on ultimate axial tensile bearing capacity of steel-tubes. These four factors are longitudinal reinforcement length rate , thickness , elastic modulus and circumferential reinforcement ways of CFRP sheets. The results show that the ultimate axial tensile bearing capacity of steel-tubes strengthened with CFRP sheets is enhanced significantly and the reinforcement effect is very good.

Abstract: In the paper, the interface crack of rubber - metal ring under the radial displacement load was studied by nonlinear finite element method, changes of the tear energy with crack dimension which extending from extrusion end and tensile end along the axial and circumferential direction to the interface was analyzed. The result is that there is a certain possibility of axial extension in the tensile end. The crack propagation is most likely to occur along the circumferential direction while is impossible along either axial or the circumferential direction in the extrusion end